The Study On Regeneration Of Acidic Cupric Chloride Etchant

Etching is an important process of the manufacture of the printed circuit board,unfortunatly,the high concentration copper waste solution is also produced in this process.It had resulted in a remarkable waste of resources and a great harm to human health and environment if they were discharged directly into natural without any further processing.Moreover,the cupric ion and the chloride ion which are contained in the waste etching solution have very high recovery value.Currently,how to deal with the massive waste etching solution is an important problem under the pressure of the increasingly rigorous for resources and the environment.In order to achieve the seamless coupling of online production and our studying,the processing line of GuangZhou Guanghe Technology Ltd.was researched by the parper,it can be infered from the result that the cuprous ion concentration in the etchant would reduced to 0.4 g/L from 1.2 g/L,and the ORP would increased jump from 447 mv to 500 mv in 25 ?.In order to achieve the cleaner production,the waste etchant was recovered by air/oxygen and the bubbling tower and packed tower were designed based on it.The results show that the elapsed time of the recovery of the waste etchant was 35 min by air and 15 min by oxygen in the bubbling tower.Moreover,the elapsed time of the recovery of the waste etchant was 24 min by air and 13 min by oxygen in the packed tower.It can be inferred from the results that about 12 min was the limit time of the method.In order to gain more economies in the process,electrolysis method using chemical precipitation of copper and chemical generating of chlorine gas from waste etchant was used by the parper.A 500 ml anodic room packed tower was designed in the parper,when the anode current reachs 1.5 A and the time that the solution goes from the bottom to the top of the tower reachs 10 min,the acid etching waste liquor could realize reusing.In the cathode chamber,when the inhibitor of the cuprous reachs twice of the standard quantity and the current density reachs 1000 A/m2,the precipitation rate of copper can be exercised to the full.Meanwhile,with the precipitation of copper and recovery of the etchant,the economic effect increased substantially.So,this method have a great future industrialization applications.